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Antonio Martín

Publications and source records attributed to Antonio Martín.

At least 19 recordsLinked to original sources
PubMed2006

Homo- and heteropolynuclear platinum complexes stabilized by dimethylpyrazolato and alkynyl bridging ligands: synthesis, structures, and luminescence.

This work describes the synthesis of cis-[Pt(C[triple bond]CPh)2(Hdmpz)2] (1) and its use as a precursor for the preparation of homo- and heteropolynuclear complexes. Double deprotonation of compound 1 with readily available M(I) (M = Cu, Ag, Au) or M(II) (M = Pd, Pt) species affords the discrete hexanuclear clusters [{PtM2(mu-C[triple bond]CPh)2(mu-dmpz)(2)}(2)] [M = Cu (2), Ag (3), Au (4)], in which both "Pt(C[triple bond]CPh)2(dmpz)(2)" fragments are connected by four d(10) metal centers, and are stabilized by alkynyl and dimethylpyrazolate bridging ligands, or the trinuclear complexes [Pt(mu-C[triple bond]CPh)2(mu-dmpz)(2){M(C/\P)}2] (M = Pd (5), Pt (6); C/\P = CH(2)-C(6)H(4)-P(o-tolyl)2-kappaC,P), respectively. The X-ray structures of complexes 1-4 and 6 are reported. The X-ray structure of the platinum-copper derivative 2 shows that all copper centers exhibit similar local geometry being linearly coordinated to a nitrogen atom and eta(2) to one alkynyl fragment. However in the related platinum-silver (3) and platinum-gold (4) derivatives the silver and gold atoms present three different coordination environments. The complexes have been studied by absorption and emission spectroscopy. The hexanuclear complexes exhibit bright luminescence in the solid state and in fluid solution (except 4 in the solid state at 298 K). Dual long-lived emission is observed, being clearly resolved in low-temperature rigid media. The low-energy emission is ascribed to MLM'CT Pt(d)/pi(C[triple bond]CPh)-->Pt(p(z))/M'(sp)/pi*(C[triple bond]CPh) modified by metal-metal interactions whereas the high-energy emission is tentatively attributed to an emissive state derived from dimethylpyrazolate-to-metal (d(10)) LM'CT transitions pi(dmpz)-->M'(d(10)).

Journal Article↗
PubMed2006

Influence of solvent and weak C-H...O contacts in the self-assembled [Pt2M4{CC(3-OMe)C6H4}8] (M = Cu, Ag) clusters and their role in the luminescence behavior.

New alkynyl complexes [Pt2M4{CC(3-OMe)C6H4}8] (M = Ag 1, Cu 2) have been synthesized and their structures and properties compared to those of related [Pt2M4(CCPh)8] compounds. For the Pt-Ag derivatives, the X-ray structures of the discrete yellow solvate monomer, [Pt2Ag4{CC(3-OMe)C6H4}8].2THF ([1.2THF]), and the dark garnet unsolvated polymeric form, [Pt2Ag4{CC(3-OMe)C6H4}8](infinity) ([1](infinity)), are presented. The yellow form ([1.2THF]) exhibits a distorted octahedral geometry of the metal centers with the platinum atoms mutually trans and the four silver atoms in the equatorial plane. Pairs of Ag atoms are weakly bridged by THF molecules [mu-Ag2...O(THF)]. The garnet form ([1](infinity)) has an unprecedented infinite stacked chain of octahedral clusters linked by short Pt...Pt bonds (3.1458(8) A). In both forms, different types of weak C-H...O (OMe) hydrogen bonds are observed. For comparative purposes, we have also provided the crystal structures of the yellow monomer form, [Pt2Ag4-(CCPh)8].CHCl3, and the red dimer form, [Pt2Ag4(CCPh)8]2 (Pt-Pt 3.221(2) A). These clusters display intense photoluminescence in both solution and the solid state, at room temperature and 77 K. The emission observed for the yellow form [1.2THF] in the solid state is assigned to a 3MLM'CT [Pt(d)/pi(CCR) --> Pt(p(z))/Ag(sp)/pi(CCR)] state modified by Pt...Ag, Ag...Ag, and Ag...(THF) contacts. However, in the garnet form [1](infinity) and in 2, the emissions are related to the axial Pt-Pt bonds and are assigned as phosphorescence from a metal-metal-to-ligand charge-transfer (3MMLCT) excited state ([1](infinity)), or an admixture of a metal-metal (Pt-Pt) centered 3(dsigmap(z)sigma) and 3MMLCT excited state (2). For 1, a remarkable quenching and a shift to higher energies in the emission is observed on changing from CH2Cl2 to THF, and for both 1 and 2, the emission spectra at 77 K varies with the concentration, showing their tendency to stack even in glass.

Journal Article↗
PubMed2006

From a trinuclear platinum(III) phosphido derivative to a platinum(II) cluster: formation of a P-C bond.

Reaction of the trinuclear Pt(III)-Pt(III)-Pt(II) [(C6F5)2Pt(III)(mu-PPh2)2Pt(III)(mu-PPh2)2Pt(C6F5)2] (2) derivative with NBu4Br or NBu4I results in the formation of the trinuclear Pt(II) complexes [NBu4][(PPh2C6F5)(C6F5)Pt(mu-PPh2)(mu-X)Pt(mu-PPh2)2Pt(C6F5)2] [X = I (3), Br (4)] through an intramolecular PPh2/C6F5 reductive coupling and the formation of the phosphine PPh2C6F5. The trinuclear Pt(II) complex [(PPh2C6F5)(C6F5)Pt(mu-PPh2)Pt(mu-PPh2)2Pt(C6F5)2] (5), which displays two Pt-Pt bonds, can be obtained either by halide abstraction in 4 or by refluxing of 2 in CH2Cl2. This latter process also implies an intramolecular PPh2/C6F5 reductive coupling. Treatment of complex 5 with several ligands (Br-, H-, and CO) results in the incorporation of the ligand to the cluster and elimination of one (X = H-) or both (X = Br-, CO) Pt-Pt bonds, forming the trinuclear complexes [NBu4][(PPh2C6F5)(C6F5)Pt(mu-PPh2)(mu-X)Pt(mu-PPh2)2Pt(C6F5)2] [X = Br (6), H (7)] or [(PPh2C6F5)(C6F5)Pt(mu-PPh2)2Pt(mu-PPh2)(CO)Pt(C6F5)2(CO)] (8). The structures of the complexes have been established on the basis of 1H, 19F, and 31P NMR data, and the X-ray structures of the complexes 2, 3, 5, and 7 have been established. The chemical relationship between the different complexes has also been studied.

Journal Article↗
PubMed2006

Quantifier variables of the back surface deformity obtained with a noninvasive structured light method: evaluation of their usefulness in idiopathic scoliosis diagnosis.

New noninvasive techniques, amongst them structured light methods, have been applied to study rachis deformities, providing a way to evaluate external back deformities in the three planes of space. These methods are aimed at reducing the number of radiographic examinations necessary to diagnose and follow-up patients with scoliosis. By projecting a grid over the patient's back, the corresponding software for image treatment provides a topography of the back in a color or gray scale. Visual inspection of back topographic images using this method immediately provides information about back deformity, but it is important to determine quantifier variables of the deformity to establish diagnostic criteria. In this paper, two topographic variables [deformity in the axial plane index (DAPI) and posterior trunk symmetry index (POTSI)] that quantify deformity in two different planes are analyzed. Although other authors have reported the POTSI variable, the DAPI variable proposed in this paper is innovative. The upper normality limit of these variables in a nonpathological group was determined. These two variables have different and complementary diagnostic characteristics, therefore we devised a combined diagnostic criterion: cases with normal DAPI and POTSI (DAPI < or = 3.9% and POTSI < or = 27.5%) were diagnosed as nonpathologic, but cases with high DAPI or POTSI were diagnosed as pathologic. When we used this criterion to analyze all the cases in the sample (56 nonpathologic and 30 with idiopathic scoliosis), we obtained 76.6% sensitivity, 91% specificity, and a positive predictive value of 82%. The interobserver, intraobserver, and interassay variability were studied by determining the variation coefficient. There was good correlation between topographic variables (DAPI and POTSI) and clinical variables (Cobb's angle and vertebral rotation angle).

Adolescent↗
PubMed2006

Chronic respiratory symptoms, spirometry and knowledge of COPD among general population.

RATIONALE: Infradiagnosis of chronic obstructive pulmonary disease (COPD) may be related to the lack of knowledge about the disease and/or the scarce use of diagnostic procedures. This study analyses the frequency of respiratory symptoms and the knowledge about COPD in the general population, together with the use of spirometry in individuals at risk of COPD. POPULATION AND METHOD: A telephone survey was carried out in 6758 subjects older than 40 years, stratified by age, habitat (urban or rural) and region, screened by random-digit dialling. RESULTS: Up to 24% reported having at least one chronic respiratory symptom and 20.9% had a self-reported respiratory diagnosis. A total of 19.2% were active smokers and 40% had never tried to quit. Only 60% of the individuals with chronic symptoms had consulted a physician and, of them, only 45% had undergone spirometry. Spirometry was mentioned more frequently by subjects attended by pulmonologists than by GPs (67.6 vs. 28.6%; P<0.001). The term COPD was identified only by 8.6% of the participants. CONCLUSIONS: Many individuals with respiratory symptoms do not request medical attention and do not attempt to quit smoking. There is a lack of knowledge about COPD. Physicians should more actively inform about the disease and increase the use of spirometry for early detection.

Aged↗
PubMed2006

Exacerbations, hospital admissions and impaired health status in chronic obstructive pulmonary disease.

Impaired health status may be a risk factor for frequent exacerbations and hospital admission and, in turn, exacerbations and admissions may further impair the health status of patients with COPD. We have investigated the variables associated with frequent exacerbations (3 or more per year) and admission, with particular interest in health status, in a cohort of ambulatory patients with moderate to severe COPD attended by chest physicians in Spain. A total of 227 investigators included 1057 patients with a mean predicted FEV1 of 41.8%. The mean total score on the St. George's Respiratory Questionnaire (SGRQ) was 47.9 units, and 300 patients (28.4%) had 3 or more exacerbations the previous year and 344 (32.6%) were admitted at least once during the same period. In multivariate analysis only the SGRQ total score was significantly associated with both frequent exacerbations (OR = 1.04; 95% CI = 1.01-2.12; p<0.0001) and admission (OR = 1.01; 95% CI = 1.00-1.02; p = 0.0008). Other variables significantly associated with frequent exacerbations were chronic mucus hypersecretion, increased baseline dyspnea, comorbidity, GOLD stage IV and treatment with inhaled corticosteroids. Variables associated with admission were lower educational level, increased number of exacerbations, use of long-term oxygen therapy and use of short acting beta-2 agonists. An impaired health status is associated with an increased number of exacerbations and with admission to hospital in the previous year. These results, together with previous studies, confirm that impairment in health status in COPD is both a marker of risk for, and a consequence of, frequent exacerbations and admissions.

Aged↗
PubMed2006

[Use of spirometry in the diagnosis and treatment of chronic obstructive pulmonary disease in primary care].

OBJECTIVE: The aim of this study was to assess the use of spirometry for the diagnosis and follow-up of patients with chronic obstructive pulmonary disease (COPD) in primary care in terms of deficiencies and the requirements for its correct use, and to identify the regimens most commonly used in patients with COPD. METHODS: The study included 839 primary care physicians, each of whom completed 2 questionnaires, one on treatment of COPD and the other on the use of spirometry for diagnosis and follow-up of the disease. RESULTS: Notable among the results was the high number of questionnaires in which no response was given to the question on classification of patients according to the severity of airway obstruction (10.7% of cases) and the low number of correct responses to questions on treatment with bronchodilators during the stable phase of COPD (15.1%). The highest rate of correct responses was for questions regarding the indication for spirometry, all of which were answered correctly in more than 60% of cases. Only 59.2% of primary health care centers performed spirometry, mainly due to a lack of training. In more than 30% of cases the nursing staff had not received specific training, a finding that was reflected in the poor compliance with guidelines for calibration (10.9% of health care centers performed daily calibrations), cleaning of the spirometer (in 13.9% of cases the equipment was never cleaned), and providing patients with pretest recommendations (30% did not provide recommendations the day before spirometry). CONCLUSIONS: Primary care physicians are aware of the usefulness of spirometry for the diagnosis and follow-up of COPD. Although they are able to recognize airflow obstruction, they do not classify patients correctly in terms of severity. Very limited availability of spirometry was observed in primary health care centers and there was little training in the use of the technique, a finding reflected in the poor compliance with guidelines for its use.

Humans↗
PubMed2005

Synthesis and in solution and solid state structural study of intramolecular Pt...H interactions in pentafluorophenyl platinum(II) complexes containing the ligands triazene, formamidine, and 2-aminopyridine.

The preparation of the [NBu4][Pt(C6F5)3L] complexes (L=triazene, formamidine, 2-aminopyridine,) have been carried out. These ligands contain a hydrogen atom, with more or less acidic character, in a position suitable for establishing an intramolecular hydrogen bonding interaction with the metal center. This interaction has been detected in solution for; its 1H NMR spectrum shows that the resonance assignable to this hydrogen has platinum satellites. For, this coupling is not observed, and the interaction, if it exists, has to be weaker because of the less acidic character of the hydrogen atom. The 2-aminopyridine ligand is more flexible than the triazene or formamidine, and also in this case, no evidence of the interaction in solution is obtained. Nevertheless, if another potential proton acceptor is present, such as ClO4- in [NBu4]2[Pt(C6F5)3(C5H6N2)](ClO4), a conventional N-H...O-Cl hydrogen bond is formed. The crystal structures of complexes have been determined by X-ray diffraction.

Amidines↗
PubMed2005

Tetranuclear platinum phosphido complexes with different structures.

The addition of [NBu4]Br or [NBu4][BH4] to solutions of [Pt4(mu-PPh2)4(C6F5)4(CO)2] yields the complexes [NBu4]2[Pt4(mu-PPh2)4(mu-X)2(C6F5)4] (X=Br, H,) in which the two CO groups have been replaced by two anionic, bridging X ligands. The total valence electron counts are 64 and 60, respectively; thus, complex does not require Pt-Pt bonds, while two metal-metal bonds are present in, as their NMR spectra confirm. Also, the NMR spectra indicate a nonsymmetrical "Pt(mu-PPh2)2Pt(mu-PPh2)(mu-X)Pt(mu-PPh2)(mu-X)Pt" disposition for and. Treatment of with HX (X=Cl, Br) yields the complexes [NBu4]2[Pt4(mu-PPh2)4(mu-H)2(C6F5)3X] (X=Cl, Br,). These complexes react with [Ag(OClO 3)PPh3] with displacement of the halide and formation of [NBu4][Pt4(mu-PPh2)4(mu-H)2(C6F5)3PPh3]. Complexes maintain the same basic skeleton as, with two Pt-Pt bonds. Complex is, however, an isomer of the symmetric [NBu4]2[{(C6F5)2Pt(mu-PPh2)2Pt(mu-Br)}2], which has been prepared by a metathetical process from the well-known [NBu4]2[{(C6F5)2Pt(mu-PPh2)2Pt(mu-Cl)}2]. The comparison of the X-ray structures of and confirms the different disposition of the bridging ligands, and their main structural differences seem to be related to the size of Br- and its position in the skeleton.

Journal Article↗
PubMed2005

In-depth profile analysis of thin films deposited on non-conducting glasses by radiofrequency glow-discharge-optical emission spectrometry.

The potential of radiofrequency glow-discharge-optical emission spectrometry (rf-GD-OES) for quantification of thin films on non-conducting materials has been investigated. A commercial rf-GD chamber from Jobin Yvon operated at 13.56 MHz with Ar as discharge gas was used. The signal integration time was 0.1 s. The effect on emission yields of thin conducting layers on glasses of different thickness was studied in detail, using the rf-GD in the common operating mode "constant pressure-constant forward power". Calibration curves were obtained for two types of material-conducting reference materials and a set of non-conductors comprising homogeneous glass of known composition and three different thicknesses coated (or not) with thin layers of gold. Qualitative and quantitative in-depth profile analyses of different coated non-conducting samples were investigated. A variety of samples, including different thick glass substrates (from 1.8 to 5.8 mm), different thin films deposited on homogeneous glasses (from 6 nm to 35 nm), and different kinds of coating (conductors such as Fe, Ni, Cr, Al, and Nb and non-conductors such as Si3N4) were studied at 450 Pa pressure and 20 W forward power. The quantitative in-depth profiles proved satisfactory and results for depths and concentrations were similar to nominal values.

Journal Article↗
PubMed2005

Mediterranean vegetable soup consumption increases plasma vitamin C and decreases F2-isoprostanes, prostaglandin E2 and monocyte chemotactic protein-1 in healthy humans.

Consumption of fruits and vegetables is associated with a reduced risk of death from all causes including heart disease and stroke. In this work, the bioavailability of vitamin C from a Mediterranean vegetable soup (gazpacho) constituted mainly of tomato, pepper and cucumber, and its influence on plasma vitamin C, 8-epi-prostaglandin F(2alpha) (8-epi-PGF2alpha), prostaglandin E2 (PGE2), monocyte chemotactic protein-1 (MCP-1), and the cytokines/tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and IL-6 concentrations in a healthy human population were assessed. Six men and six women consumed 500 ml of commercial gazpacho per day for 14 days, corresponding to an intake of 78 mg of ascorbic acid per day. There were no differences (P = .22) in baseline plasma vitamin C concentrations between the men and women. The maximum increase (P < .05) in plasma vitamin C occurred 4 h postdose in both men and women. Vitamin C concentrations were significantly higher (P < .03) on Days 7 and 14 of the intervention. Baseline concentrations of uric acid and 8-epi-PGF2alpha were significantly higher (P < or = .032) in men than in women. Baseline concentrations of 8-epi-PGF2alpha decreased significantly (P < or = .05) by Day 14 of the intervention. A significant inverse correlation was observed between vitamin C and 8-epi-PGF2alpha (r = -.415, P = .049). Baseline concentrations of PGF2 and MCP-1 were significantly higher (P< or = .025) in men than in women but decreased significantly (P< or = .05) by Day 14 of the intervention. No effect on TNF-alpha, IL-1beta and IL-6 was observed at Day 14 of the intervention. Drinking gazpacho (500 ml/day) significantly increases plasma concentrations of vitamin C and significantly decreases 8-epi-PGF2alpha, PGE2 and MCP-1 concentrations in healthy humans.

Adult↗
PubMed2005

New homoleptic organometallic derivatives of vanadium(III) and vanadium(IV): synthesis, characterization, and study of their electrochemical behaviour.

The arylation of [VCl3(thf)3] with LiR(Cl), where R(Cl) is a polychlorinated phenyl group [C6Cl5, 2,4,6-trichlorophenyl(tcp), or 2,6-dichlorophenyl (dcp)] gives four-coordinate, homoleptic organovanadium(III) derivatives with the formula [Li(thf)(4)][V(III)(R(Cl))(4)] (R(Cl) = C(6)Cl(5) (1), tcp (2), dcp (3)). The anion [V(III)(C6Cl5)4]- has an almost tetrahedral geometry, as observed in the solid-state structure of [NBu4][V(C6Cl5)4] (1') (X-ray diffraction). Compounds 1-3 are electrochemically related to the neutral organovanadium(IV) species [V(IV)(R(Cl))4] (R(Cl) = C6Cl5 (4), tcp (5), dcp (6)). The redox potentials of the V(IV)/V(III) semisystems in CH2Cl2 decrease with decreasing chlorination of the phenyl ring (E(1/2) = 0.84 (4/1), 0.42 (5/2), 0.25 V (6/3)). All the [V(IV)(R(Cl))4] derivatives involved in these redox couples could also be prepared and isolated by chemical methods. The arylation of [VCl(3)(thf)(3)] with LiC6F5 also gives a homoleptic organovanadium(III) compound, but with a different stoichiometry: [NBu4]2[V(III)(C6F5)5] (7). In this five-coordinate species, the C6F5 groups define a trigonal bipyramidal environment for the vanadium atom (X-ray diffraction). EPR spectra for the new organovanadium compounds 1-6 are also given and analysed in terms of an elongated tetrahedral structure with C(2v) local symmetry. It is suggested that the R(Cl) groups exert a protective effect towards the vanadium centre.

Journal Article↗
PubMed2005

[Colorectal laparoscopy in the Canary Islands. A multicenter study of 144 patients].

INTRODUCTION: To analyze the short-term results of laparoscopic colorectal surgery (LCRS) in the Canary Islands. MATERIAL AND METHODS: A questionnaire was sent to hospitals performing laparoscopy and retrospective data on demographic, perioperative and pathological variables in 144 patients who underwent LCRS between May 1993 and May 2003 were obtained. RESULTS: Sixty-five men and 79 women underwent colon (n=126) and rectal (n=18) surgery in the last 16 months of the study period. The most frequently performed procedure was sigmoidectomy in 85 patients (59%). The most frequent diagnosis was colon adenocarcinoma in 73 patients (50%), followed by diverticular disease in 36 patients (25%). The mean values of the variables studied were: body mass index, 27.3 (range, 22-35); operating time, 175 min (range, 60-255); blood loss, 183.6 ml (range, 50-500). Peristalsis reinitiated at 45 h; oral diet was introduced at 67 h and the overall mean length of hospital stay was 7.8 days (range, 3-30). The length of hospital stay was significantly longer in patients with complications (14.5 vs 6.4; p <.01). There were 7 conversions (4.86%). There were no perioperative deaths. The overall morbidity rate was 28%. The most frequent early complication was surgical wound infection in 9 patients (6.2%). Anastomotic leak was detected in 5 patients (3.4%). CONCLUSIONS: LCRS has been shown to be a safe and effective technique that has recently increased in the centers surveyed. The factor with the greatest influence on length of hospital stay was the development of postoperative complications.

Adult↗
PubMed2005

Intake of Mediterranean vegetable soup treated by pulsed electric fields affects plasma vitamin C and antioxidant biomarkers in humans.

The bioavailability of vitamin C from pulsed electric fields (PEF)-treated vegetable soup in comparison with freshly made (FM) vegetable soup-gazpacho-and its impact on 8-epiPGF(2alpha) and uric acid concentrations in a human population were assessed. For this purpose six subjects consumed 500 ml PEF-treated vegetable soup/day, and six subjects consumed 500 ml FM vegetable soup/day for 14 days. On the first day of the study, the subjects drank the vegetable soup in one dose (dose-response study), and on days 2-14 they consumed 250 ml in the morning and 250 ml in the afternoon (multiple-dose-response study). Blood was collected every hour for 6 h on the first day and again on days 7 and 14. All blood samples were analyzed for vitamin C, 8-epiPGF(2alpha), and uric acid. The maximum increase in plasma vitamin C occurred 3 h post-dose in both the PEF and the FM groups. Vitamin C remained significantly higher (P = 0.05) on days 7 and 14. The plasma 8-epiPGF(2alpha) concentration was significantly lower at the end of the study in both the PEF group (P = 0.002) and the FM group (P = 0.05). Plasma levels of vitamin C and 8-epiPGF(2alpha) were inversely correlated in both groups (r= -0.549, P = 0.018; and r = -0.743, P = 0.0004, respectively). To summarize, drinking two servings (500 ml) of PEF-treated or FM gazpacho daily increases plasma vitamin C and significantly decreases 8-epiPGF(2alpha) concentrations in healthy humans.

Adult↗
PubMed2004

Synthesis and characterization of pentachlorophenyl-metal derivatives with d0 and d10 electron configurations.

By reaction of [TiCl(3)(thf)(3)] with LiC(6)Cl(5), the homoleptic organotitanium(III) derivative [Li(thf)(4)][Ti(III)(C(6)Cl(5))(4)] (1) has been prepared as a paramagnetic (d(1), S = 1/2, g(av) = 1.959(2)), extremely air-sensitive compound. Oxidation of 1 with [N(C(6)H(4)Br-4)(3)][SbCl(6)] gives the diamagnetic (d(0)) organotitanium(IV) species [Ti(IV)(C(6)Cl(5))(4)] (2). Compounds 1 and 2 are also electrochemically related (E(1/2) = 0.05 V). The homoleptic, diamagnetic (d(10)) compounds [N(PPh(3))(2)][Tl(C(6)Cl(5))(4)] (3) and [Sn(C(6)Cl(5))(4)] (4) have also been prepared. Nearly tetrahedral environments have been found for the d(0), d(10), and d(1) metal centers in the molecular structures of compounds 2-4 as well as in that of [Li(thf)(2)(OEt(2))(2)][Ti(III)(C(6)Cl(5))(4)].CH(2)Cl(2) (1') (X-ray diffraction). The reaction of the heavier Group 4 metal halides, MCl(4) (M = Zr, Hf) with LiC(6)Cl(5) in the presence of [NBu(4)]Br gives, in turn, the heteroleptic species [NBu(4)][M(C(6)Cl(5))(3)Cl(2)] (M = Zr (5), Hf (6)). Compounds 5 and 6 are isomorphous and isostructural, with the metal center in a trigonal-bipyramidal (TBPY-5) environment defined by two axial Cl ligands and three equatorial C(6)Cl(5) groups (X-ray diffraction). No redox features are observed for compounds 3-6 in CH(2)Cl(2) solution between -1.6 and +1.6 V.

Journal Article↗